Aluminum magnesium titanate is a ceramic containing Al, Mg and Ti as constituent elements. In Patent Literatures 1, 2 and 3, a method of forming a mixture containing aluminum source powder, magnesium source powder, titanium source powder and silicon source powder to obtain a molded body, and sintering the obtained molded body is disclosed as a method for producing aluminum magnesium titanate. Specifically, when the elemental composition ratio of Al, Mg, Ti and Si in the mixture is represented by compositional formula (1):Al2(1−x)MgxTi(1+x)O5+aAl2O3+bSiO2   (1),in Patent Literature 1, an example using a mixture in which x is 0.50, a is 0.01 to 0.05 and b is 0.02 to 0.25 is disclosed, in Patent Literature 2, an example using a mixture in which x is 0.25 to 0.95, a is 0.1 and b is 0.1 is disclosed, and in Patent Literature 3, an example using a mixture in which x is 0.08, a is 0.07 and b is 0.08 is disclosed. According to such a production method, aluminum source powder, magnesium source powder and titanium source powder can react with each other by sintering to obtain target aluminum magnesium titanate.